Pinion forming machine



PINION FORMING MACHINE LLz! fing.

09h 10, 1950 w. P. GALLAGHl-:R 2,525,029

PINIQN FORMING MACHINE Filed Dec. 28, 194e S sheets-sheet 2 Oct. 10,' 1950 w. P. GALLAGHER PIN-ION FORMING MACHINE 5 sheets-sheet :s

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PINION FORMING MACHINE 5 Sheets-Sheet 5 Filed nec. 28, 1946 'STOP Patented Oct. 10, 1950 anatre iJNiTED STATES PhfiiNT @FP1 CE 2,525,029 PINION FQRMING MACHENIE William 13. Gallagher, Chicago,- Ill., assigner .to Vlntcrnationai"Register Company, Chicago, Ill.,

a corporation of Illinois Application December 28, 1946, Serial No. 718,946

4 Claims.

My invention relates, generally, to broaching machines and it has particular relation to multiple broach machines for cutting pinion teeth or the like in round rods of indeterminate lengths,

Among the objects of my invention are: To -cut pinion teethV or the like in a rod of indeterminate length; to cut the teeth in `a stepwise fashion without elongation of the rod; to cut the teeth progressively from one end of the rodto the other; to push and pull the rod in a step-bystep manner through the plurality of 4dies Voi succeedinglyv smaller dimension in tandem; tov form the individual pinions or the like by cutm ting the toothed rod inte the desired lengths; to grip the rod ahead of and behind the dies and then to move the gripping means translatorily for pushing and pulling the rod through the dies; to grip the rod iirst and then move the gripping means in a forward direction, then to release the gripping means and thereafter return the same to repeat the cycle; to employ a hydraulic power unit for 4grirmng the rod at `each point; to employ a'hydraulic power unit for shiiting the clamping means forward and back;

and to operate `the hydraulic power units sequen-- tally, first to grip the rod, next to move the rod forwardlyY throughthe dies, next to release the hydraulic unit which clamps the rod, and finally to return the clamping means to the initial position.

Other objects of my invention will, in part, be obvious and in part appear hereinafter.

Accordingly, my invention is disclosed in the embodiment thereof shown in the accompanying drawings and it comprises the features ofV together which: Figure l is a top plan view oi a multiple breach machine in which my invention is embodied;

Figure 2 a view, in side elevation, of Athe ne shown in Figure 1;

re 3 is a view, partly in section, which Shows how the pinion teeth are gradually cnt in a. rod, the teeth being fully formed at the end gradually diminishing in height to the other end;

Figure /i is a detail sectional vie-w, atan en- 2 Y larged scale, taken-along the line li-d lof Figure 2;

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VFigure 5 is a detail sectional view taken along the line 5 5 of Figure 4;

vFigure 6 is a detail sectional View, at an enf larged scale, taken .along the line e--f of Figur-e1;

Figure 7 is a vdetail sectional view, atan enlarged scale, taken along the line l-l of Fig? ure i2; Y

Figure 8 is a .top plan view of a number of the hydraulic power units that are employed for operating the clamping heads Yshowing the manner in which the high pressure 'hydraulic connections are made thereto while permitting the same to be moved translatorily;

Figure 9 is a detail sectional View, taken along the line @-9 of Figure l0 and showing the details of .construction of the die block and the manner in which the .die is `mounted thereon;

Figure 10 is a detail sectional view, taken along the line i-lt'of Figur-e 9, showing further details `of construction of the die block and the manner in which the die is mounted thereon;

"Figure 11 is a view, in front elevation, of a typical die that may be employed in practicing this invention; and

Figure l12 illustrates, 'diagrammatically, the hydraulic and electrical connections that can be employed in practicing this invention.

Referring now particularly to Figures 1 and 2 of the drawings, it will be observed that the reference character i0 designates, generally, a machine bed, such as the bed of a lathe, which is supported by suitable legs Il, l2 and I3. The machine b ed Hi, in accordance with the present invention, may be about 12 feet long. However, it will be understood that it Ymay be longer or shorter as circumstances may dictate 'for a particular application ofthe invention. The machine bed I0 may be provided with a'trough I4 for collecting a'coolant fluid that is supplied to the cutting zone in a manner which will be described hereinafter. The multiple breach machine may be powere by a hydraulic power unit i6 of the cylinder and piston type which may be mounted for horizontal operation at the left-hand end of the machine bed lil by angularly directed support plates I1. The power unit IE operates through a connecting rod I8 to move a yoke I9 that is attached thereto. A pair of rods 20 are secured to the yoke I9 and extend through movable clamping heads 2l that are arranged to move translatorily with the rod 2B. As will appear hereinafter, the clamping heads 2l are arranged to clamp a rod 22 -on opposite sides of stationary die blocks 23 for pushing and pulling the rod 22 therethrough without elongation. The rod 22 may be a round rod, the outer diameter of which equals the major diameter of the pinions -or the likethat are to be cut. It may be formed of brass or other alloys suitable for use in making pinions, ratchets, splines, keyways or the like. The rods 22 may be of indeterminate length. However, for convenience, they may be used in twelve foot lengths and fed through the stationary die blocks 23 by the movable clamping heads 2| as will be described hereinafter.

For cooling the cutting zones along the rod 22 a suitable coolant in the form of a liquid may be supplied from a suitable source through a conduit 26 that communicates with a distributing conduit 21 to which individual flexible conduits 28 are connected, as illustrated in Figures 1, 2 and 7 of the drawings. Each of the conduits 28 may have a nozzle 29 for directing the flow of the coolant to the cutting zones.

The hydraulic power unit I6 is energized for reciprocating the rods and therewith the clamping heads 2| from a suitable source of hydraulic pressure. As will appear hereinafter, the application of hydraulic pressure is controlled both electrically'and mechanically. It may be necessary to stop the operation of the machine from any position therealong. For this purpose an emergency operating rod 32 extends along the machine. It may be movably supported by links 33 and it may be arranged to operate a normally closed switch 34. v

The necessary pressure for operating the hydraulic power unit |6 and for operating certain additional hydraulic power units which will be referred to hereinafter, may be obtained from a suitable pump 35, Figure 1, that may be driven by a motor 36. The hydraulic fluid for operating the system may be pumped from and returned to a suitable sump 31 on which the motor `36 and pump 35 driven thereby may be mounted.

The motor 36 may be started and stopped independently of the control of the. hydraulic system. For this purpose a start switch 38 and a stop switch 39 may be mounted at a convenient location on the machine bed l0, as illustrated in Figure 2. The hydraulic system can be controlled by a start switch 40 and a stop switch 4| located nearby. The details of the electrical circuit and of the hydraulic system are shown in Figure 12 and will be described after a description of the machine itself has been set forth.

Before describing in detail how the teeth for pinions, ratchets, splines, keyways or the like are cut in the rod' 2|, reference may be had to the illustration of the rod 22 in Figure 3, which shows the appearance of the rod while it is passing through theseveral stationary die blocks 23. It will be understood that the rod 22 is fed into .the machine from the right-hand end as viewed in Figures 1 and 2. The initial cut at the righthand end on the rod 22 is indicated at 42 in Figure 3. As the rod progresses through the die blocks 23, the cut is increased at each station, which'corresponds to a die block 23 until, as indicated at 43, the pinion teeth are fully formed.

In practicing the present invention it has been found desirable to employ 24 stations corresponding to 24 die blocks 23. A corresponding number of movable clamping heads 2| is employed. How ever, it will be understood that a larger or smaller number of stations can be used, depending uPQl'l the circumstances. 4 l A Referring now particularly to Figures 4 and 5 of the drawings, it will be observed that the machine -bed Il) includes side members 44 and 45 which extend the entire length of the machine. Each movable clamping head 2|, which is secured to and moved by the rods 20 relative to the side members 44and 45, carries a clamp block 46 which may be accurately positioned thereon by dowel pins, one of which is indicated at 4l. Each clamp block 46 may be secured to its individual clamping head 2| by counter-sunk screws, one of which is indicated at 48. Each clamp block 46 has a transversely extending slot 49 which permits the lower portion 5U thereof to be flexed relative to the upper portion of the clamp block 46 which is held rigid. The clamp block 46 is apertured toreceive a split clamp bushing the halves of which are indicated at 5| of Figure 5. The parts making up the clamp bushing 5| may be held in place 4by suitable set screws 52.

The internal diameter of the split clamp bushing 5| is the same as the external diameter of the rod 22. When a different diameter of rod 22 is machined, a different set of clamp bushings 5| is used. The slot 49 in the clamp block 46 and the spacing between the halves 5| of the clamp bushing are such that, when the lower portion 56 of the clamp block 46 is flexed upwardly, the rod 22 is securely clamped between the parts of the clamp bushing 5|. For this purpose a hydraulic power unit 53 of the cylinder and piston n type is provided underneath each of the clamping heads 2| and is movable therewith. Each power unit 53 operates through a connecting rod 54 that bears against the underside of the portion 56 of the clamp block 46. Each power unit 53 is arranged to have a stroke of about 1/16 inch.

As illustrated in Figure 8, the hydraulic power units 53 are arranged in groups of three and interconnected by suitable conduits 55. A flexible conduit 56 interconnects the intermediate power unit 53 of each group to the main conduit 51 to which hydraulic fluid under pressure is supplied through suitable control means from the pump 35. This arrangement permits the use of a single flexible conduit 56 for three of the power units 53, thereby reducing the number that would otherwise be required if a flexible conduit were provided for each of the power units 53.

As illustrated in Figure 4, the conduits 2'! and 5'! extend along the side member 44 and may be secured in spaced relation therealong by clamps 58 and 59 that may be held by bolts 60 extending into the side member 44.

As illustrated in Figure 6 of the drawings, the rods 20 are provided with sleeves 64, one sleeve for each clamping head 2|. Each sleeve 64 has an end section 65 of reduced diameter which has a press t with the clamping head 2| associated therewith. The sleeves 64 are placed in end-toend relation on the rods 2U between the yoke |9 at the left-hand end and the nut at the righthand end. In this manner the clamping heads 2| are held in accurate spaced relation for conjoint movement on operation of the power unit I6. The power unit I6 is arranged to have a stroke of about 2 inches so that the clamping heads 2| move the rod 22 forwardly through about this distance on each forward stroke of the power unit I6.

Also as illustrated in Figure 6 of the drawings, the sleeves 64 are slidably mounted in bushings 66 that are located in the stationary die blocks 23. The stationary die blocks 23 then serve as guides for the rods 20 and the clamping heads 2|.

Referring now to Figure 7 of the drawingsQit side members 44 and 45 are provided' with ways 68 and 69 to which the stationary die blocks 23 may be clamped by .suitable bolts lll that .extend i into a-clamp plate ll individual to each .die `block 23. The ways 158 and FEB are accurately machined so that the die blocks 23 can be located in exact alignment therealong and clamped in place as described. A .suitable lubricant may be sup-plied to the bushings' throughlgrease fittings 1.2 1ocated on the upper side of each die block 23. The die blocks 23 additionally are held in aligned spaced relation by through bolts F3 with `which tubular spacers 14 cooperate.' As illustrated in Figure 6, the spacers "M are positioned between the adjacent faces of the die blocks 23 and the bolts 13 extend through them and through the `die blocks 23.

The manner in which the cutting dies are mounted in the die blocks 23 is illustratedvin Figures 9 and 10 of the drawings. 'As there shown, each die block 2e is apertured, as indicated at Tl, for receiving a sleeve 'i8 that surrounds an inner guide bushing i9. The inner guide bushing 19 bears against the rear side of a cutting die 8E) and both are held in place by an outer .guide bushing 8l thatk may be secured to the die block 23, by bolts 82, Figures 7 and 9. The lower portion of the cutting die B is cut away to provide a flat surface asindicated at 33 for coop- .erating with a locating yblock 8d having a corre-` sponding surface and which is held in place in the die block 23 by suitable screws 85 and 85' and a dowel pin 86. In this manner the cutting dies 8D are accurately located in alignment and the teeth 8'.' thereof are also located in exact alignment.

1t will be understood that each cutting die is of slightly smaller dimension for each of thev succeeding stations from the right-hand end of the broaching machine to the left-hand end. As indicated in Figure l1, the major diameter 8B of the teeth 3l' is the same for each of the cutting dies e0. the teeth 3l' is the variable factor. The minor diameter 89 varies from amaximurn for the cut- Yting die 80 in the rst station at the right-hand end of the machine to a minimum for the last or twenty-fourth station at the left-hand end vof the machine. Thus, the cutting dies 8i) for the succeeding stations are of succeedingly 'smaller dimension, the difference residing in the gradual decrease in the minor `diameter 59 for the teeth el of each of the succeeding cutting dies 813. Of course, the dimensions and number of teeth 871 will vary in accordance with the size and number of pinion teeth that are required for the finished .pinio-ns.

the hydraulic power unit 53 individual thereto. f

It will be understood that all of the hydraulic power units 53 are simultaneously operated but, initially the rod 22 is only gripped by the first clamping head 2|. Thereafter, the power unit ,i6 is energized to move all of the clamping heads However, the minor diameter 8e for 'will be observed that the Aupper portionswof the Y 2`| through the :forward stroke. Accordingly, the rod 22 is pushed through the rst stationary die block 23 and the initialV formation of the teeth takes' place on the rod 22v as indicated at 42 in Figure 3e' The first cutting die 80 frictionally grips the rodY 22 sumciently to hold the rod stationary when the first clamping head 2l is unclamped and vsubsequently the hydraulic unit I6 moves it and the other clamping heads 2l through the back stroke. This cycle of operations is repeated and the rodv 22 is moved in a stepwise fashion through the cutting vdies 8U of the stationary die blocks 23. When the rod v22 has moved past the rst die block 23, it can be.

gripped on opposite sides thereof by the rst and second clamping heads 2l. On the next forward stroke of the hydraulic unit I6, the rod 22 is not only pushed through the cutting die 8i! of the first station but also is pulled therethrough. Because of this combined pushing and `pulling action no elongation `of the rod 22 takes place. As the rod 22 progresses through the several stations, it is individually pushed and pulled through each one. Since the rod 22 is securely clamped at each station and no slippage occurs, the force applied by the power unit lf during the forward stroke is individually applied at the corresponding points along Vthe rod 22. As a result, no elongation of the rod 22 takes place and .the pin-- ion teeth, as .indicated -at i3 in Figure 3 of the drawings, are accurately formed.

After thezpin-ion teeth d3 have been cut in the rod 22 the individual pinions may be formed by suitably transversely cutting the rod 22 up into Vthe desired lengths to provide the required length of pinion. This cutting operation may be performed in any suitable manner, such as by a suitable cutting wheel or saw or by a shearing operation.

. Various control means may be employed for eiecting the sequential operation of the hydraulic power units I6 and 53 to move the rod 22 through the cutting dies 8l? in a step-by-step manner. It is required that provision be made for rst energizing the hydraulic units 53 individual to the clamping heads 2l for securely clamping the rod 22 on opposite sides of the stationary die blocks 23. Only after this is accomplished is the hydraulic power unit le energized- .to move the clamping heads 2i with a translatory movement to simultaneously push and pull the rod -22 through the cutting dies 230.

At the end of the forward stroke and before the power unit le is reversed to eiect the return stroke, the power units 53 are deenergized by release of hydraulic pressure therefrom to unclanip the rod 22. Thereafter the hydraulic unit It is energized in the reverse direction to return the clamping heads 2l to the initial position, wher-eupon the cycle lcan be repeated.

In Figure 12 are illustrated the electrical and hydraulic connections and apparatus that can be used for controlling the seouential operation of the hydraulic units it and 53 in the manner just described. As there shown, a relay 92 can be provided for control'ing the energization of the :rotor Sii. It will be noted that the motor 35 is a three phase motor and that it may be` energized from a suitable three phase circuit, which isY indicated by conductors lll-LZ--L3- These conductors may be connected to a suitable three phase alternating current source, such as a E50-cycle source, operating at 220 volts between phases. The relay 92 Amay be provided with norfarsazsgoze may be provided with an operating winding 93, the energization of which is controlled by the start and stop switches 38 and 39.

For starting the motor 36, it will be obvious that when start switch 38 is closed, a. circuit is completed through normally closed `stop switch 3-9 for energizing the winding 93 from conductors III-L3. A holding circuit is provided for the winding 93 when the contacts 92a are closed. The motor 38 can be deenergized merely by operating the stop switch 39. This opens the energizing circuit to the winding 93 and the relay 92 automatically operates to the open position.

For controlling the hydraulic system relays 94 and 95 may be employed. Relay 94 is provided with normally opened contacts 94a-94b and an operating winding 96. Likewise relay 95 may have normally opened contacts 95a-95b and an operating winding 91. The relay 95 at the contact 95a is arranged to control the energization of the solenoid valve 98 which, when deenergized, is in the open position. When the solenoid valve 98 is deenergized, hydraulic pressure from the pump 35 is not .permitted to build up in the relief valve 99. Rather, the hydraulic fluid circulates through the relief valve 99 back to the sump 31.

The functioning of the hydraulic system may be controlled by a four way pilot valve which has operating arms |0| and |02 that are arranged to be engaged by operating fingers |03 and |04, respectively, which may be commonly mounted on a support that, in turn, is secured to one or more of the clamping heads 2|, It will be understood that the pilot valve |09 is reversed at the ends of the forward and reverse strokes of the clamping heads 2| to effect the reciprocatory movement thereof. The operating nger |03 is an extension of a plate |08 which has an inclined surface |01 for engaging a roller |98 to open a normally closed limit switch |09. As will appear hereinafter, the limit switch |09 is .provided to insure that the clamping heads 2| will always be returned to the end of the return stroke when the stop switch 4| is operated.

When the solenoid valve 98 is energized on energization of the relay 95, fluid pressure builds up through a check valve and into a control valve ||2. Thence, the hydraulic fluid ows to a sequence valve ||3 which is arranged to energize the hydraulic power units 53 through a reducing valve ||4 prior to application of fluid pressure to the hydraulic unit I6 for moving the clamping heads 2| through the forward stroke. The control valve ||2 is controlled by the pilot valve |00 to cause the hydraulic uid to flow through a check valve ||5 and a flow control valve IB for energizing the hydraulic power unit 6 to accomplish the return stroke of the clamping heads 2| after the pressure applied to the hydraulic units 53 for gripping the rods 22 has been relieved.

In operation, the motor 38 is energized in the manner described by operating the start switch 38. 'Ihe pump 35 is driven to generate the required hydraulic pressure.

A pump (not shown) is then started to cause coolant to flow through the conduit 26, distribution conduit 21 and exible conduits 28 to be discharged through the nozzles 29 into the passageway between the outer surface of the cutting die 89 and the inner surface of the central portion of the outer guide bushing 8|. The start switch 49 is momentarily operated to complete obvious circuits for energizing operating windings 96 and 91 of the relays 94 and 95. Holding circuits are completed for these windings through contacts 94h and 95h, respectively. The holding circuit for winding 96 extends through the contacts of stop switch 4|, while the holding circuit for winding 91 extends through the normally closed contacts of emergency switch 34 and contacts 94a of relay 94.l On closure of contacts 95a, the energizing circuit for the solenoid valve 98 is completed, it is closed and hydraulic pressure is applied to the hydraulic system for operating it in the manner described.

As long as the solenoid valve 98 remains energized, the hydraulic operating unit I6 will reciprocate the clamping heads 2| under the control of the pilot valve |00. The sequence valve ||3 controls the energization of the hydraulic power units 53 individual to the clamping heads 2| to insure the proper sequential operation.

In the event that the stop switch 4| is operated during the forward or reverse stroke of the clamping heads 2|, it is desirable that they complete the cycle of operation and return to the end of the return stroke. It is for this purpose that the normally closed limit switch |99 is provided. When the stop switch 4| is operated, the holding circuit for the winding 96 of the relay 94 is opened and this relay operates to the open position. The holding circuit for the winding 91 through contacts 94a is opened. However, this holding circuit is completed through the normally closed contacts of the limit switch |09 which are in parallel of the contacts 94a. The limit switch |99 is opened only when the power unit I6 has operated the clamping heads 2| to the end of the return stroke. At that time the holding circuit for the winding 91 is opened and the relay 95 operates to the open position. Contacts a are opened and the energizing circuit for the solenoid valve 98 is opened. When the emergency stop switch 34 is operated, the broaching machine does not complete the cycle of operation. Rather, it is stopped immediately upon operation of the switch 34 by the rod 32. It will be observed that the normally closed contacts of the emergency stop switch 34 are connected in series with the contacts 94a and the contacts of the limit switch |99. Accordingly, as soon as the switch 34 is opened, the holding circuit for the winding 91 is opened, relay 95 operates to the open position and the solenoid valve 98 is deenergized.

While this invention has been described particularly with respect to the making of pinions, as indicated hereinbefore, it may be used for broaching teeth for ratchets, splines, keyways or any other like devices that have a similar pattern.

Since certain further changes can be made in the foregoing construction and diierent embodiments of the invention can be made without departing from the spirit and scope thereof, it is intended that all matter shown in the accompanying drawings and described hereinbefore shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. Means for cutting pinion teeth in a rod which comprises, in combination, a plurality of stationary die blocks positioned in tandem; a die carried by each die block, each die being of smaller dimension than the preceding die, a plurality of movable clamping heads each individual to a die block and positioned ahead of the same, a split clamp bushing carried by each clamping head for gripping the rod, a hydraulic power unit of the cylinder and piston type individual to 9 each clamping head for operating the same to cause the rod to be gripped by each clamp bushing, operating means mechanically interconnecting said clamping heads whereby the same can be shifted with a translatory movement, a hydraulic power unit of the cylinder and piston type connected to said operating means, and means for applying hydraulic fluid pressure from a source thereof to said power units individual to said clamping heads for gripping the rod and thereafter to said power unit connected to said operating means for pushing and pulling the rod through said dies.

2. The invention, as set forth in claim 1, wherein means are provided for releasing the pressure from the hydraulic power units individual to the clamping heads at the end of the forward stroke of the hydraulic power unit connected to the operating means and for energizing the latter unit to return said clamping heads to their initial positions.

3. The invention, as set forth in claim 1, wherein the hydraulic power unit connected to the operating means moves the same through a distance about equal to the distance between the stationary die blocks to move the rod forwardly through the dies in a stepwise manner.

WILLIAM P. GALLAGHER.

REFERENCES CITED The following references are of record in the file of this patent: .l

UNITED STATES PATENTS Numher Name Date Re. 15,464 Blanchard Oct. 10, 1922 772,841 Smith Oct. 18, 1904 1,096,856 Pederquist May 19, 1914 2,102,071 Hart Dec. 14, 1937 2,234,728

Gaines Mar. 11, 1941 

